1. Field of the Invention
The invention relates to tracking objects and more particularly to a method of tracking a tracking object and a non-tracking object for identification even when overlap occurs.
2. Description of Related Art
Conventionally, an original image is converted into a binary image having either a value of 1 (i.e., image of interest) or value of 0 (i.e., image of don't care) based on features such as skin color of an object or view distance or calculation (e.g., background addition or subtraction) in object tracking. This has the benefits of sharp contrast and reliability.
Positions and ranges of different objects in the binary image can be obtained by analyzing connected elements of the binary image. The relative positioning is critical to the effectiveness of tracking. Tracking is easy when two objects are spaced. However, tracking may be very difficult or even fail due to overlapping.
Thus, distance state of two objects is thus very important. There are three states, i.e., separation, proximity and overlap between any two objects of interest. An object to be tracked is first taken as an object of interest. Next, a state of the object with respect to another object is determined by detection.
It is defined that separation means there is a great distance (i.e., greater than a predetermined distance) between a tracking object and a non-tracking object, proximity means the distance between the tracking object and the non-tracking object is less than the predetermined distance, and overlap means the tracking object extends over and partly cover the non-tracking object to formed a connected object. The overlap can make object tracking more difficult and even cause failure.
The invention discussed later aims to increase the effectiveness of two overlapping objects.